Photoacid generating monomer and precursor thereof

ABSTRACT

A monomer compound has the formula (I): 
     
       
         
         
             
             
         
       
         
         
           
             where each R 1 , R 2 , and R 3  is independently H, F, C 1-10  alkyl, fluoro-substituted C 1-10  alkyl, C 1-10  cycloalkyl, or fluoro-substituted C 1-10  cycloalkyl, provided that at least one of R 1 , R 2 , or R 3  is F; n is an integer of from 1 to 10, A is a halogenated or non-halogenated C 2-30  olefin-containing polymerizable group, and G +  is an organic or inorganic cation. The monomer is the reaction product of a sultone precursor and the oxyanion of a hydroxy-containing halogenated or non-halogenated C 2-30  olefin-containing compound. A polymer includes the monomer of formula (I).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a nonprovisional filing of U.S. provisionalapplication No. 61/428,999 filed on Dec. 31, 2010, the content of whichis incorporated herein by reference in its entirety.

BACKGROUND

Disclosed is a polymerizable photoacid generating monomer, and a sultoneprecursor compound for the monomer.

Advanced photolithographic techniques for imprinting desired patterns onsilicon wafers generally rely upon acid-catalyzed deprotection of estersto acids in the poly(methacrylate) photoresist polymers as the keychemical reaction for transferring the pattern in order to induce asolubility change. This catalytic process, referred to as chemicalamplification, is induced by irradiation of a photo-sensitive reagent orphotoacid generator (PAG). PAGs used in photoresist polymers may consistof two parts: a sulfonate anion, and a tris(hydrocarbyl)sulfonium cationwhich usually has at least one aromatic group, where the cation absorbsa photon and decomposes to generate one acid proton, which leads tomultiple desirable acid-catalyzed chemical reactions. Sulfonic acidsuperacids, e.g., alkyl or arylsulfonic acids having fluorinesubstituents generally within 2 or 3 bond lengths of the sulfur atom,are preferred in some applications.

As advances in photolithographic techniques lead to patterns withincreasingly finer resolution, acid diffusion in the photoresist matrixbecomes a concern. Acid diffusion may be impeded by, in one approach,tethering the conjugate base of the acid (e.g., a sulfonate anion) tothe polymer, restricting the acid to a limited volume and more evenlydistributing the PAG in the photoresist matrix.

U.S. Patent Application Publication No. 2009/0202943 A1 discloses apositive-tone resist which includes a polymer prepared from an acrylateor methacrylate monomer having a photoactive sulfoniumfluoroalkylsulfonate salt (i.e., the conjugate base of a superacid)tethered to it through a (meth)acrylate monomer linkage. One exemplarysuch monomer is prepared by condensing the triaryl sulfonium salt of1,1-difluoro-2-hydroxyethylsulfonate with (meth)acrylic anhydride. Whilesuch a condensation can in principle be used, the synthesis of the anioninvolves a three-step synthesis from commercially available precursors,and the precursors are limited due to the possibility of side-reactionswith the cation and/or the polyfunctional anion.

STATEMENT OF INVENTION

The above and other deficiencies of the prior art may be overcome by acompound having the formula (I):

wherein each R¹, R², and R³ is independently H, F, C₁₋₁₀ alkyl,fluoro-substituted C₁₋₁₀ alkyl, C₁₋₁₀ cycloalkyl, or fluoro-substitutedC₁₋₁₀ cycloalkyl, provided that at least one of R¹, R², or R³ is F; n isan integer of from 1 to 10, A is a halogenated or non-halogenated C₂₋₃₀olefin-containing polymerizable group, and G⁺ is an organic or inorganiccation.

A polymer comprises the compound of formula (I).

A sultone precursor for a monomer has the formula (XVI):

wherein each R is independently F, C₁₋₁₀ alkyl, fluoro-substituted C₁₋₁₀alkyl, C₁₋₁₀ cycloalkyl, or fluoro-substituted C₁₋₁₀ cycloalkyl,provided that at least one R is F; n is an integer of from 0 to 10, andm is an integer of 1 to 4+2n.

A monomer comprises the reaction product of the sultone precursor and anoxyanion of a hydroxy-containing or carboxy-containing halogenated ornon-halogenated C₂₋₃₀ olefin-containing compound.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention are apparent from the following detailed description taken inconjunction with the accompanying drawings in which:

FIG. 1 shows a thermogravimetric analysis plot of mass loss versustemperature for an exemplary monomer;

FIG. 2 is an ORTEP plot of the potassium salt of an exemplary monomerbased on X-ray crystallographic analysis; and

FIG. 3 is a deep ultraviolet (DUV) lithography contrast curve as a plotof feature size (in Angstroms) versus exposure dose (in millijoules persquare centimeter, mJ/cm²) for a polymer prepared using an exemplaryphotoacid generator monomer.

DETAILED DESCRIPTION

Disclosed herein is a sultone precursor for a monomer, and novelolefinic monomers useful as photoacid generators (herein, PAGs) fromfluorinated sultone precursors. As used herein, “sultone” refers to acyclic sulfonate ester which is capable of undergoing ring-openingattack by addition of a nucleophile, where the ring-opening nucleophilicattack is specific to the carbon atom alpha to the sultone ring oxygen.Preferably, the sultone is fluorinated with one or more fluorine atoms,and still more preferably, the sultone may include a geminaldifluoromethylene group alpha to the sulfonate sulfur atom. Where thenucleophile used in the ring-opening reaction is a carboxylic acid suchas (meth)acrylic acid, or a hydroxystyrene or hydroxymethyl styrene, theproduct of the reaction with the sultone may be useful as a monomer forradical polymerization. The nucleophile, in these instances, may be theoxyanion of one of these compounds, and may be prepared by the reactionof a base with (meth)acrylic acid or styrene carboxylic acid, ahydroxystyrene (having a phenolic group) or a hydroxymethylstyrene(having a benzylic alcohol moiety).

The ring-opened product of the sultone is thus very cleanly obtained inhigh yield. A photoacid generator having low diffusion and lowoutgassing properties may further be prepared from the ring-openedproduct by metathesis in which the cation of the ring-opened product isexchanged for a photoactive cation, such as an onium cation having atleast one phenyl group. Such a monomer, preferably when polymerized intoa polymer and used in photoresist compositions generates acid whenexposed to radiation for advanced lithographies such as for e-beam,x-ray, and extreme ultraviolet (EUV) radiation having a wavelength of13.4-13.5 nm. Such monomers desirably have low acid diffusion, and canprovide high contrast and good line shape. Further, the decompositionproducts of these PAGs may be reduced relative to conventionalnon-polymer bound PAGs, under similar conditions of photoresistcomposition, exposure, and processing.

As used herein “onium” refers to iodonium or sulfonium cations. Also asused herein, “substituted” means including a substituent such as ahalogen (i.e., F, Cl, Br, I), hydroxy, amino, thiol, carboxyl,carboxylate, amide, nitrile, thiol, sulfide, disulfide, nitro, a C₁₋₁₀alkyl, a C₁₋₁₀ alkoxy, a C₆₋₁₀ aryl, a C₆₋₁₀ aryloxy, a C₇₋₁₀ alkylaryl, a C₇₋₁₀ alkyl aryloxy, or a combination comprising at least one ofthe foregoing. It will be understood that any group or structuredisclosed with respect to the formulas herein may be so substitutedunless otherwise specified, or where such substitution wouldsignificantly adversely affect the desired properties of the resultingstructure. Also, “(meth)acrylate” as used herein means either acrylateor methacrylate, and is not limited to either of these unless otherwisespecified.

The monomer is a compound having the general formula (I):

where each R¹, R², and R³ is independently H, F, C₁₋₁₀ alkyl,fluoro-substituted C₁₋₁₀ alkyl, C₁₋₁₀ cycloalkyl, or fluoro-substitutedC₁₋₁₀ cycloalkyl, provided that at least one of R¹, R², or R³ is F.Exemplary groups R¹, R², and R³ may include, in addition to one or morefluorine atoms, alkyl groups such as methyl, ethyl, n-propyl, isopropyl,n-butyl, 2-butyl, isobutyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methylbutyl,3-methylbutyl, n-hexyl, n-heptyl, n-octyl, 3-octyl, n-decyl, or any ofthe foregoing alkyl groups having one or more fluorine substituentsincluding trifluoromethyl groups, 2,2,2-trifluoroethyl, perfluoroethyl,perfluorobutyl, or the like; or cycloalkyl groups such as cyclobutyl,cyclopentyl, 1-methylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, 1- or2-adamantyl, 1- or 2-decalinyl; or any of the foregoing cycloalkylgroups having one or more fluorine substituents includingperfluorocyclopentyl, 3,5-bis(trifluoromethyl)cyclohexyl,perfluorocyclohexyl, or the like. More preferably, R¹, R², and R³ areindependently a combination of H and F.

Also in formula (I), n is an integer of from 1 to 10, and preferably, nis 1, 2, or 3. In formula (I), the total number of substituents R¹, R²,and R³ (other than hydrogen) may therefore be 4+2n. The monomer mayinclude only a single R¹, R², or R³ non-hydrogen substituent (where thesubstituent is F), or more than one substituent (other than hydrogen) isincluded in addition to the F group. Alternatively, substituents R¹, R²,and R³ are not F.

Also in formula (I), A is a halogenated or non-halogenated C₂₋₃₀olefin-containing polymerizable group, and G⁺ is an organic or inorganiccation.

In particular, A is the reaction residue of a nucleophile. While thenucleophile may include any nucleophilic group which can react with theprecursor sultones disclosed hereinbelow, the nucleophile is preferablya polymerizable group which may react under polymerization conditionssuch as radical, anionic, cationic, or controlled free-radicalpolymerization methods to provide a polymer. Preferably, the nucleophileis the oxyanion of a hydroxy-containing halogenated or non-halogenatedC₂₋₃₀ olefin-containing compound, where A is thus the reaction residueof the nucleophile which provides the halogenated or non-halogenatedC₂₋₃₀ olefin-containing polymerizable group A.

Preferably, the nucleophile is the oxyanion of a C₃₋₂₀ vinyl carboxylicacid, a hydroxy-containing C₅₋₂₀ vinyl carboxylate, or a C₇₋₂₀ vinylhydroxyaromatic compound. Hydroxyaromatic compounds, where used, mayinclude phenolic hydroxy groups, or non-phenolic hydroxy groups such asbenzylic hydroxy groups, or pendant hydroxy groups.

Exemplary nucleophiles include the oxyanion of unsaturated carboxylicacids such as (meth)acrylic acid, (meth)acryloyl acetic acid, maleic orfumaric acid, citraconic acid, itaconic acid, hydroxyl-containing(meth)acrylate esters such as 2-hydroxyethyl (meth)acrylate and2-hydroxypropyl (meth)acrylate, carboxylic acids of norbornenes such as5-norbornene-2-carboxylic acid and 5-norbornene-2,3-dicarboxylic acid,hydroxyl-containing (meth)acrylate esters such as 2-hydroxyethyl(meth)acrylate and 2-hydroxypropyl (meth)acrylate; hydroxystyrenes suchas o, m, or p-hydroxystyrene, or vinylbenzyl alcohols such as 4-vinylbenzyl alcohol.

Preferably, the compound has the formula (II) or (III):

wherein each R², R³, and R⁴ is independently H, F, C₁₋₁₀ alkyl, or C₁₋₁₀fluoroalkyl, n is 1 or 2, A-O is a C₃₋₂₀ vinyl carboxylate group, ahydroxy-containing C₅₋₂₀ vinyl carboxylate group, or a C₇₋₂₀ vinylaryloxy compound, and G⁺ is an organic or inorganic cation.

More preferably, the compound has the formula (IV), (V), (VI), (VII), or(VIII):

wherein each R², R³, R⁴, R⁵, R⁶, and R⁷ is independently H, F, C₁₋₁₀alkyl, or fluoro-substituted C₁₋₁₀ alkyl, each R⁸ is independently F,C₁₋₁₀ alkyl, or fluoro-substituted C₁₋₁₀ alkyl, L is a halogenated ornon-halogenated C₁₋₃₀ alkylene group, C₂₋₃₀ alkenylene group, monocyclicor polycyclic C₃₋₃₀ cycloalkylene group, monocyclic or polycyclic C₆₋₃₀arylene group, or monocyclic or polycyclic C₇₋₃₀ alkylene-arylene group;k and l are each independently integers of 0 to 5 and where k is 0, l is1; m is an integer of 0 to 4; n is 1, 2, or 3; and G⁺ is an organic orinorganic cation.

The compound may more preferably be of the formula (IX, (X), (XI),(XII), or (XIII):

wherein R⁵ and R⁷ are independently H, F, C₁₋₁₀ alkyl, orfluoro-substituted C₁₋₁₀ alkyl, and G⁺ is an organic or inorganiccation. Preferably, R⁵ and R⁷ are independently H or —CH₃.

The monomer, in addition to the anionic structure provided by thereaction of the sultone with the nucleophile, includes a cation G⁺ wherethe cation may be any cation associated with the nucleophile (i.e., asthe cation of the salt of the nucleophile). In this way, the cation maybe, for example, an inorganic cation including an alkali metal cation,such as lithium, sodium, potassium, rubidium, cesium, an alkaline earthmetal cation such as magnesium, calcium, barium, or strontium; a maingroup metal cation such as aluminum, tin, lead, or bismuth, or atransition metal cation such as copper, zinc, iron, nickel, cobalt, orsilver; or the cation may be an organic cation such as an ammoniumcation including ammonium, alkylammonium including mono-, di-, tri-, andtetraalkylammonium such as triethylammonium, tetramethylammonium,tetrabutylammonium, trimethylbenzylammonium, or cetylammonium; animinium ion; a guanidinium ion, an alkylphosphonium cation; or an oniumcation of iodine or sulfur substituted with alkyl, aryl, or aralkylgroups. A combination comprising at least one of the foregoing may beused. Preferably, the cation is an onium cation which isphotodecomposable, and hence the monomer is also photodecomposable,i.e., is a photoacid generator (PAG) monomer.

The PAG monomers disclosed herein are based on a cation-anion structurein which the cation is preferably an aryl-substituted onium (i.e.,disubstituted iodonium or trisubstituted sulfonium) cation, such as atriphenyl sulfonium cation, or of a structure in which the substituentaryl groups are further attached to one or more adjacent aryl groups in,for example, a heterocycle structure which includes the onium, or aspart of a fused aromatic ring system.

Where the monomer is photodecomposable, i.e., where the reaction productof the oxyanion nucleophile and the sultone is a salt having a first,non-photodecomposable cation, the method further comprises exchangingthe first, non-photodecomposable cation for a second cation of theformula (XIV):

wherein X is S or I, each R⁰ is independently a halogenated ornon-halogenated group comprising a C₁₋₃₀ alkyl group; a polycyclic ormonocyclic C₃₋₃₀ cycloalkyl group; a polycyclic or monocyclic C₆₋₃₀ arylgroup; or a combination comprising at least one of the foregoing, andoptionally two R⁰ groups are further attached to one another by a singlebond where each R⁰ is independently a monocyclic C₆₋₃₀ aryl group, and ais 2 or 3, where when X is I, a is 2, or when X is S, a is 3.

Preferably, G has the formula (XV), (XVI), or (XVII):

wherein X is I or S, R⁹, R¹⁰, R¹¹, and R¹² are each independentlyhydroxy, nitrile, halogen, C₁₋₁₀ alkyl, C₁₋₁₀ fluoroalkyl, C₁₋₁₀ alkoxy,C₁₋₁₀ fluoroalkoxy, C₆₋₂₀ aryl, C₆₋₂₀ fluoroaryl, C₆₋₂₀ aryloxy, orC₆₋₂₀ fluoroaryloxy, Ar¹ and Ar² are independently C₁₀₋₃₀ fused orsingly bonded polycyclic aryl groups; R¹³ is a lone pair of electronswhere X is I, or a C₆₋₂₀ aryl group where X is S; and p is an integer of2 or 3, wherein when X is I, p is 2, and where X is S, p is 3, q and rare each independently an integer from 0 to 5, and s and t are eachindependently an integer from 0 to 4.

Exemplary PAG cations G⁺ include the following structures:

wherein X is S or I provided that where X is I, R′ is a lone pair ofelectrons, R is C₁₋₁₀ alkyl, C₁₋₁₀ fluoroalkyl, C₁₋₁₀ alkoxy, or C₁₋₁₀fluoroalkoxy group, where X is S, R′ is a C₆₋₃₀ aryl, C₆₋₃₀ arylene, orC₇₋₂₀ alkyl-aryl group, each R″ is independently H, OH, halogen, C₁₋₂₀alkyl, C₁₋₂₀ fluoroalkyl, C₁₋₂₀ alkoxy, C₁₋₂₀ fluoroalkoxy, C₃₋₂₀cycloalkyl, C₃₋₂₀ fluorocycloalkyl, C₆₋₂₀ aryl, C₇₋₂₀ alkyl-aryl, or acombination comprising at least one of the foregoing, and each R″′ isindependently H, C₁₋₂₀ alkyl, C₁₋₂₀ fluoroalkyl, C₁₋₂₀ alkoxy, C₁₋₂₀fluoroalkoxy, C₃₋₂₀ cycloalkyl, C₃₋₂₀ fluorocycloalkyl, C₆₋₂₀ aryl,C₇₋₂₀ alkyl-aryl, or a combination comprising at least one of theforegoing.

Exemplary monomers of general formula (I) include:

wherein R⁵ is H, F, C₁₋₆ alkyl, or C₁₋₆ fluoroalkyl. Preferably, R⁵ is Hor —CH₃.

The foregoing monomers may be prepared from a precursor sultone of theformula (XVIII):

with a nucleophile having a polymerizable group. In formula (XVIII),each R is independently F, C₁₋₁₀ alkyl, fluoro-substituted C₁₋₁₀ alkyl,C₁₋₁₀ cycloalkyl, or fluoro-substituted C₁₋₁₀ cycloalkyl, provided thatat least one R is F. It will be generally understood herein that whereno R or other substituent is specified for a carbon atom, the valency ofeach such carbon atom is filled with a hydrogen atom(s). Exemplarygroups R may include, in addition to one or more fluorine atoms, alkylgroups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl,isobutyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl,n-hexyl, n-heptyl, n-octyl, 3-octyl, n-decyl, or any of the foregoingalkyl groups having one or more fluorine substituents includingtrifluoromethyl groups, 2,2,2-trifluoroethyl, perfluoroethyl,perfluorobutyl, or the like; or cycloalkyl groups such as cyclobutyl,cyclopentyl, 1-methylcyclopentyl, cyclohexyl, 1-methylcyclohexyl, 1- or2-adamantyl, 1- or 2-decalinyl; or any of the foregoing alkyl groupshaving one or more fluorine substituents including perfluorocyclopentyl,3,5-bis(trifluoromethyl)cyclohexyl, perfluorocyclohexyl, or the like.More preferably, R is F.

Also in formula (XVIII), n is an integer of from 0 to 10, andpreferably, n is 1, 2, or 3. The sultone may include m substituents R,where m is an integer of 1 to 4+2n. The sultone may include only asingle R group substituent (where the substituent is F, and n is 1), ormore than one substituent may be included in addition to the F group,where the total number of substituents R is limited to the number ofsultone ring carbon atoms 2+n in which each ring carbon has up to 2substituents for a maximum of 2×(2+n) or 4+2n substituents. Preferably,the total number of substituents is defined where m is an integer of 1to 4. Alternatively, m may be 0, and/or R is not F.

Preferably, the sultone is of the formulas (XIX), (XX), or (XXI):

where each R is independently F, C₁₋₁₀ alkyl, or fluoro-substitutedC₁₋₁₀ alkyl, provided that at least one R is F; a is an integer of 1 to6, b is an integer of 1 to 8, and c is an integer of 1 to 10.

The sultone may more preferably be of the formula (XXII):

where R¹⁴, R¹⁵, R¹⁶, and R¹⁷ are each independently H, F, C₁₋₁₀ alkyl,or fluoro-substituted C₁₋₁₀ alkyl, provided that at least one of R¹⁴,R¹⁵, R¹⁶, or R¹⁷ is F. Preferably, at least one of R¹⁴, R¹⁵, or R¹⁶ maybe a fluorine atom, where each remaining R¹⁴, R¹⁵, and/or R¹⁶ is H, andR¹⁷ is H. Also preferably, both R¹⁴, R¹⁵, and/or R¹⁶ are fluorine atoms,where any remaining R¹⁴, R¹⁵, and/or R¹⁶ is H, and R¹⁷ is H.

Still more preferably, the sultone may be of the formulas (XXIII) or(XXIV):

where R¹⁵ and R¹⁶ are each independently H, F, C₁₋₁₀ alkyl, orfluoro-substituted C₁₋₁₀ alkyl, provided that at least one of R¹⁵ or R¹⁶is F. Preferably, at least one of R¹⁵ or R¹⁶ may be a fluorine atom,where each remaining R¹⁵ and/or R¹⁶ is H. Also preferably, both R¹⁵and/or R¹⁶ include fluorine, where any remaining R¹⁵ and/or R¹⁶ is H.

Exemplary sultones of general formula (XVIII) include those of theformulas:

The sultones may themselves be generally prepared by dehydrativelycyclizing a precursor alpha-omega alcohol-sulfonic acid compound in thepresence of heat. The cyclization may be carried out at a temperature ofup to 250° C., preferably 50 to 200° C. Heating at these temperaturesmay be for any time necessary to achieve cyclization in a sufficientyield. Azeotropic dehydration may also be used to remove water bydistilling from a solution that forms a water azeotrope (such as usingbenzene/water or toluene/water), or reactive distillation with removalof water generated during cyclization may be used. Alternatively, adehydrating agent such as 1,3-dicyclohexylcarbodiimide may be used, orthe cyclization may be carried out under dehydrating acidic conditionssuch as with an anhydride (e.g., acetic anhydride) or sulfuric acid.

The alpha-omega sulfonic acid compounds which can be cyclized to formthe sultones may themselves be prepared by methods such as by formingthe sulfinic acid from the corresponding alpha-omega hydroxy-bromocompound. In this reaction, the bromine group is displaced by sodiumdithionite (Na₂S₂O₄) in the presence of a weak base such as sodiumbicarbonate to form the intermediate alpha-omega hydroxy sulfinate,followed by oxidation of the sulfinate to the corresponding sulfonate.Oxidation of the sulfinate may be carried out using any suitable method,such as oxidation with aqueous potassium permanganate or an aqueoussolution of a peroxide such as hydrogen peroxide. The alpha-omegahydroxy sulfonate salt may then be converted to the correspondingsulfonic acid by treating directly with acid, or by protonation using asolid acid source such as a cation-exchange resin. Useful such resinsinclude sulfonic acid strong cation exchange resins such as Amberlite™120H or Amberlyst™ 15H resins, available from Rohm and Haas Company.

The method of preparing the monomer includes reacting the sultone with anucleophile as described hereinabove. Reacting, used in this context,means addition of the nucleophile to the carbon alpha to the sulfoneoxygen, with ring opening of the sulfone. Preferably, the nucleophile isthe oxyanion of a carboxy- or hydroxy-containing halogenated ornon-halogenated C₂₋₃₀ olefin-containing compound. More preferably, thenucleophile is the oxyanion of a C₃₋₂₀ vinyl carboxylic acid, a C₈₋₂₀vinyl aromatic carboxylic acid, a hydroxy-containing C₅₋₂₀ vinylcarboxylate, hydroxy-containing C₅₋₂₀ vinyl ether or precursor thereof,or a C₇₋₂₀ vinyl hydroxyaromatic compound. Hydroxyaromatic compounds,where used, may include phenolic hydroxy groups, or non-phenolic hydroxygroups such as benzylic hydroxy groups, or pendant hydroxy groups.

The oxyanion is formed by reacting a hydroxy-containing halogenated ornon-halogenated C₂₋₃₀ olefin-containing compound with a base having apKa for a conjugate acid thereof of greater than 12, provided the baseused is sufficiently basic to effect deprotonation of the protonatedprecursor of the nucleophile, and provided the base is itselfsufficiently non-nucleophilic so that significant reaction with otherfunctionality in the nucleophile does not occur. Bases useful for thispurpose may, depending on the acidity of the proton for the conjugateacid of the nucleophile, include carbonate bases such as lithiumcarbonate, sodium carbonate, potassium carbonate, rubidium carbonate,cesium carbonate, sodium hydrogen carbonate, and guanidinium carbonate;hydroxide bases such as lithium hydroxide, sodium hydroxide, potassiumhydroxide, rubidium hydroxide, and cesium hydroxide; alkoxide bases suchas sodium methoxide, sodium ethoxide, sodium isopropoxide, sodiumt-butoxide, potassium methoxide, potassium ethoxide, potassiumisopropoxide, potassium amylate, or potassium t-butoxide; amido basessuch as lithium diisopropylamide, sodium diisopropylamide, potassiumdiisopropylamide, lithium hexamethylsilazide, sodium hexamethylsilazide,potassium hexamethylsilazide; amine bases such as trimethylamine,triethylamine, diethylisopropylamine, diisopropylamine, t-butylamine,proton sponge, cyclohexylamine, aniline, pyridine,N,N-dimethylaminopyridine, 4-pyrrolidinopyridine, pyrazine, pyrrole,piperidines, N-methyl piperidines, 2,2,6,6-tetramethylpiperidine,tetramethylethylene diamine, diaminocyclohexane,N,N,N′N′-tetramethylcyclohexane, diazabicyclononane (DBN),diazabicycloundecane (DBU), and Troger's base; hydride bases such aslithium hydride, sodium hydride, potassium hydride, rubidium hydride,cesium hydride, calcium hydride; Grignard reagents or organolithiumreagents such as methyl magnesium chloride or n-butyllithium; alkalimetals such as Li, Na, K, Rb, and Cs, either directly reacted with theprecursor of the nucleophile or dissolved in a medium such as ammonia(Li/NH₃) or graphite (e.g., KC₈). Preferably, the oxyanion is generatedby use of a hydroxide (e.g., NaOH or KOH), alkoxide (e.g., sodiumethoxide or potassium t-butoxide), carbonate (e.g., Na₂CO₃, or NaHCO₃)or hydride (NaH or KH) base. Where the oxyanion is the anion of a phenolor alcohol, the reaction conditions are most preferably deprotonation ofthe alcohol/phenol using NaH or KH in an aprotic, non-enolizablesolvent.

Reacting of the sultone with the nucleophile may be carried out in asolvent. Useful solvents for this purpose may include water, ammonia,ethers such as ethyl ether, diisopropyl ether, methylphenyl ether,diphenyl ether, tetrahydrofuran, dioxane, or dioxolane; alcohols such asmethanol, ethanol, isopropanol, t-butanol, 2-methylpropanol, methylcellosolve, or ethyl cellosolve; acetonitrile; amides such asN,N-dimethylformamide, N,N-dimethyl acetamide, N-methylpyrrolidone,1,3-dimethyl-2-imidazolidinone, and hexamethyl phosphoramide;dimethylsulfoxide, and sulfolane. Reacting conditions are notparticularly limited and may be carried out at a temperature of up toabout 250° C., and for a time suitable to effect ring-opening addition.

PAG cations may be included in the monomer may be performed by a cationexchange reaction, sometimes referred to herein a metathesis reaction,in which a first cation/anion pair A⁺C⁻ reacts with a secondcation/anion pair B+D⁻ in solution to form the exchanged products A⁺D⁻and B⁺C⁻. Metathesis (i.e., ion exchange) reactions may be carried out,for example, in a biphasic medium where a low-activitycation/high-activity anion such as for example, triphenylsulfoniumbromide, may be exchanged with a high-activity cation/low-activity anionsuch as, for example, the sodium or potassium salt of(4-sulfo-3,3,4,4-tetrafluorobutyl-2-methyl-2-propenoate). The biphasicmedium may be any suitable biphasic medium, and preferably one having anaqueous phase for dissolving and removing the resulting high-activitysalt (e.g., NaBr or KBr in the illustrative example) and an organicmedium such as ether, or preferably dichloromethane, for dissolving andremoving the low activity salt (e.g., the triphenylsulfonium salt of4-sulfo-3,3,4,4-tetrafluorobutyl-2-methyl-2-propenoate). Exchange may becarried out at ambient temperature, for a time suitable to effectexchange equilibrium, where solvents, amounts, and times may bedetermined by the skilled artisan.

The monomers including the PAG monomers disclosed herein may bepolymerized with comonomers suitable for copolymerization with them.Preferably, where the monomer is a PAG monomer, the PAG monomer ispolymerized to form a copolymer with one or more comonomers havingacid-sensitive groups, and optionally, with other comonomers to provideother properties such as etch control, dissolution rate control, andadhesion. Such copolymers may be useful in photoresists, preferably forEUV lithography, and may desirably have specific absorbance anddecomposition characteristics when exposed to EUV radiation, overradiation of other wavelengths. For example, the EUV radiation source,in addition to an emission spectrum in the EUV region (about 12-14 nm,where the typical emission used is 13.4-13.5 nm) may emit at longerwavelengths to which photoacid generators may be sensitive, such as at248 nm and/or 193 nm (which are also emission bands for KrF and ArFexcimer lasers used in DUV and 193 nm lithographies).

The invention is further illustrated by the following examples.

All compounds used herein are available commercially except where aprocedure is provided below. Nuclear magnetic resonance (NMR) spectrawere obtained using a Varian INOVA 300 (FT 300 MHz, ¹H; 282 MHz, ¹⁹F)spectrometer. Chemical shifts for ¹H and ¹⁹F spectra were referencedinternally to tetramethylsilane or to internal solvent resonances andare reported relative to tetramethylsilane.4-Bromo-3,3,4,4-tetrafluoro-1-butanol was obtained from SynquestLaboratories. All other reagents, unless otherwise specified, wereobtained from Aldrich. Solvents were obtained from Aldrich or FisherScientific.

Thermogravimetric analysis (TGA) was obtained using a TA InstrumentsQ5000 Thermogravimetric Analyzer operating under nitrogen at atemperature ramp rate of 5° C./min.

X-ray crystallographic data was obtained using a Bruker SMART X2Sbenchtop crystallographic system. APEX2 Version 2009.9 software (BrukerAXS Inc.) was used for preliminary determination of the unit cell.Determination of integrated intensities and unit cell refinement wereperformed using SAINT Version 7.68A software (Bruker AXS Inc., 2009).Data were corrected for absorption effects with SADABS Version 2008/1software (Bruker AXS Inc.) using the multiscan technique.

Example 1 Preparation of 2-methyl-2-propenoic acid,4-sulfo-3,3,4,4-tetrafluorobutyl ester, sodium salt (1:1) A. Preparationof sodium 4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfinate intermediate

4-bromo-3,3,4,4-tetrafluoro-1-butanol (5.00 g, 22.2 mmol) was added to aslurry of NaHCO₃ (5.60 g, 66.67 mmol) and Na₂S₂O₄ (11.61 g, 66.67 mmol)in 15 mL of acetonitrile and 22 mL of water. The mixture was heated atabout 55° C. for two days in a wax bath while stirring. The slurry wasallowed to settle and an aliquot was removed which showed the reactionto be complete by ¹H NMR (D₂O). The reaction mixture was filtered andthe volatiles were removed under reduced pressure on a rotary evaporatorto provide the sulfinate salt intermediate as a white solid, which wasplaced back in the wax bath and heated over the weekend under reducedpressure at 80° C. A ¹⁹F NMR spectrum confirmed the identity of thesulfinate salt intermediate. ¹⁹F NMR (D₂O) d −112.55 (dd, 2F), −131.30(dd, 2F).

B. Preparation of sodium 4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonateintermediate (Small Scale)

The above prepared solid was dissolved in 25 mL of water, cooled to 0°C. and 5 mL of 50% aqueous H₂O₂ (w/w) was added under generation ofsteam. After stirring for 1 hour, NMR spectra were taken of an aliquotwhich showed that the reaction was about 50% complete. Additional (5 mL)H₂O₂ was added and the stirring was continued. NMR analysis showed thereaction to be complete. The volatiles were removed under reducedpressure on a rotary evaporator to give a white solid. Peroxide teststrips were used to confirm the presence of peroxide in the condensate,which was discarded, and in the solid which had been redissolved inwater. Sodium bisulfite was added until no peroxide remained. The slurrywas filtered and the volatiles were removed on a rotary evaporator togive the sulfonate salt as a white solid. ¹⁹F NMR (D₂O) d −112.44 (dd,2F), −117.08 (dd, 2F).

C. Preparation of sodium 4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfinateintermediate (Larger Scale)

4-Bromo-3,3,4,4-tetrafluoro-1-butanol (19.92 g, 88.54 mmol) was added toa slurry of NaHCO₃ (22.31 g, 265.6 mmol) and Na₂S₂O₄ (46.25 g, 265.6mmol) in 60 mL of acetonitrile and 88 mL of water. The mixture washeated at about 55° C. for two days in a wax bath without stirring dueto the large amount of solids present. ¹⁹F NMR spectra showed almost noconversion to product. The temperature was then increased to about 80°C. As the temperature increased, sufficient of the inorganic salts(NaHCO₃ and Na₂S₂O₄) dissolved to allow for stirring of the mixture.Additional sodium dithionite (17 g) and sodium bicarbonate (15 g) wereadded. NMR spectra showed that further reaction had occurred. Thereaction mixture was allowed to cool to ambient temperature andadditional water (100 mL) and acetonitrile (100 mL) were added so thatall the solid material dissolved. NMR spectra were taken of each layer.The aqueous layer contains sulfinate and perhaps a small amount ofsulfonate, but no starting bromide, while the acetonitrile layer shows aconsiderable amount of starting material. The layers were separated. Theaqueous layer was set aside, and additional sodium dithionite (30 g) andsodium carbonate (38 g) were added to the acetonitrile layer (200 mL)along with about 100 mL of water. The reaction mixture was heated atabout 85° C. overnight. The solution was cooled, filtered, combined withthe previously separated aqueous layer, and the volatiles were removedon a rotary evaporator. The resulting crunchy solid was washed withabout 200 mL of ether and dried under vacuum.

D. Preparation of sodium 4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonateintermediate (Larger Scale)

The above prepared solid was dissolved in 25 mL of water, cooled to 0°C. in an ice bath and 50 mL of aqueous 50% H₂O₂ (w/w) was added undergeneration of steam. The reaction mixture was allowed to stir overnight.¹⁹F NMR spectra showed the reaction to be about 90-95% complete.Additional (20 mL) of the H₂O₂ solution was added and the stirring wascontinued until NMR analysis showed the reaction to be complete. Sodiumbisulfite was then added until no peroxide remained. The slurry was thenfiltered and the volatiles were removed on a rotary evaporator to give awhite solid having the same characteristic properties as described inExample 1, part B.

E. Preparation of 4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonic acidintermediate

The white solid from Example 1, part D, which contained sodium4-hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonate, was extracted withmethanol (ca. 200 mL) and filtered to remove particulates. The resultingpale yellow solution was passed through a column packed with about 8 cmof Amberlite™ 120H acidic cation exchange resin to provide a light brownsolution of the protonated compound as the sulfonic acid. Additionalmethanol was used to flush out any remaining sulfonic acid. Thevolatiles were removed under reduced pressure to give a dark brown oilcontaining black particulate specks. The yield was 15.5 g, 77.2% basedon starting 4-bromo-3,3,4,4-tetrafluoro-1-butanol.

The sulfonic acid was characterized by thermogravimetric analysis (TGA)under nitrogen atmosphere, and at a temperature ramp rate of 5° C./min.FIG. 1 shows the thermogravimetric (TGA) plot data, where it can be seenthat decomposition of the sulfonic acid proceeds steadily with loss ofabout 30% mass until about 150° C. is reached, at which pointdecomposition accelerates with the maximum rate of decompositionoccurring at a temperature of 159.6° C., and with the compound reachingcomplete loss of mass at a temperature of about 245° C.

F. Preparation of 3,3,4,4-tetrafluorobutanesultone

4-Hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonic acid (2.00 g, 8.84 mmol)was placed in a 5-mL round-bottom flask attached to a short-pathdistillation column. The system was placed under a nitrogen atmosphere.The flask was immersed in a hot wax bath and the temperature wasgradually raised from 130° C. to 180° C. While this temperature rise wasoccurring, water began to distill up into the cooler regions of thedistillation apparatus. The apparatus was disassembled and the flask wasreconnected to a microdistillation apparatus and heating under nitrogenwas resumed. The pressure was gradually decreased so that the productsultone and water distilled over and formed a two-phase liquid product.The lower sultone layer was removed by pipette, dried over anhydrousmagnesium sulfate, and filtered through a pipette filter to give theproduct as a colorless liquid.

G. Preparation of 3,3,4,4-tetrafluorobutanesultone (Larger Scale)

4-Hydroxy-1,1,2,2-tetrafluorobutane-1-sulfonic acid (6.78 g, 30.0 mmol)was placed in a 50-mL round-bottom flask attached via a V-tube to aSchlenk tube. The system was placed under vacuum and the Schlenk tubewas immersed in liquid nitrogen. The flask containing the sulfonic acidwas immersed in a hot wax bath and the temperature was gradually raisedto about 160° C. The product sultone and water gradually distilled overand froze in the receiver vessel. After thawing, two layers formed. Thelower sultone layer was removed by pipette, dried over anhydrousmagnesium sulfate, and filtered to give the product as a colorlessliquid (3.85 g, 61.7%).

H. Preparation of 2-methyl-2-propenoic acid,4-sulfo-3,3,4,4-tetrafluorobutyl ester, sodium or potassium salt (1:1)

NMR tube scale, sodium salt (1:1): Sodium hydride (0.029 g, 1.2 mmol)was added slowly to methacrylic acid (0.103 g, 1.2 mmol) in 1 mL ofCD₃CN. After stirring overnight, 3,3,4,4-tetrafluorobutanesultone (0.250g, 1.2 mmol) was added and the mixture was transferred to an NMR tube.The reaction progress was monitored by ¹H NMR. The mixture was graduallyheated up to 75° C. at which time the reaction was complete.

Bulk scale, potassium salt (1:1): Methacrylic acid (1.708 g, 19.85 mmol)was added slowly to potassium hydride (1.150 g, 28.66 mmol) in 40 mL ofTHF. After stirring overnight, the reaction mixture was filtered and thevolatiles were removed under reduced pressure.3,3,4,4-Tetrafluorobutanesultone (3.260 g, 15.66 mmol), methacrylic acid(2.0 mL), and a small amount of hydroquinone were added to the potassiummethacrylate and the mixture was then heated overnight at 75° C. Acetone(10 mL) was added to the mixture. The solids were filtered out andwashed with additional acetone and dried under reduced pressure. Thesolids were then extracted with water and filtered. The volatiles wereremoved under reduced pressure to give a white crystalline solid (4.10g, 78.8%).

FIG. 2 shows an ORTEP plot of the structure of the product,2-methyl-2-propenoic acid, 4-sulfo-3,3,4,4-tetrafluorobutyl ester,potassium salt (1:1). Crystals suitable for a single crystal x-raydiffraction study were grown by evaporation of an aqueous solution ofthe product of Example 1, part H (Bulk scale). The crystals grew in theform of flat colorless needles. The data sets were collected in astraightforward manner using a Bruker SMART X2S bench topcrystallographic system. XPREP Version 2008/2 software (Bruker AXS Inc.)determined the space group to be P1 21/c 1, with Z=4 for the formulaunit, C₈H₉F₄KO₅S. The structure was solved with XS Version 2008/1software (Bruker AXS Inc.) and subsequent structure refinements wereperformed with XL Version 2008/4 software (Bruker AXS Inc.). The finalanisotropic full-matrix least-squares refinement on F_(o) ¹ with 173variables converged at R₁=5.11% for the observed data and with R₂=16.75%for all data.

Example 2 Preparation of triphenylsulfonium1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate

Potassium 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate (2g, 6.02 mmol) and triphenylsulfonium bromide (2.25 g, 6.57 mmol) wereadded to a 100-mL round bottom flask, along with 15 mL ofdichloromethane and 15 mL of distilled, deionized water. The mixture wasvigorously stirred for 36 hours. Stirring was stopped and the mixtureseparated into two clear layers; the organic layer was washed twice with30 mL of 1% (w/w) aqueous ammonium hydroxide and five times with 30 mLof distilled, de-ionized water. The organic layer was dried over sodiumsulfate and filtered. Hydroquinone (1 mg) was added and the solvent wasremoved by rotary evaporation and high vacuum to yield the product as acolorless, viscous oil (2.65 g, 4.76 mmol). ¹H NMR (d₆-acetone): 7.9(br), 6.1 (s), 5.6 (s), 4.4 (t), 2.8 (m), 1.9 (s); ¹⁹F NMR (d₆-acetone):−112.7 (s), −119.7 (s).

Example 3 Preparation of phenyl dibenzothiophenium1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate

Potassium 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate(1.91 g, 5.75 mmol) and phenyl dibenzothiophenium bromide (2.14 g, 6.27mmol) were added to a 100-mL round bottom flask, along with 15 mL ofdichloromethane and 15 mL of distilled, de-ionized water. The mixturewas vigorously stirred over the weekend. Stirring was stopped and themixture separated into two clear layers; the organic layer was washedtwice with 30 mL of 1% aqueous ammonium hydroxide and five times with 30mL of distilled, deionized water. Dichloromethane was removed by rotaryevaporation and high vacuum to yield the product as a white powder (2.41g, 4.35 mmol). ¹H NMR (d₆-acetone): 8.6 (d), 8.4 (d), 8.0 (t), 7.8 (br),7.6 (t), 6.1 (s), 5.6 (s), 4.4 (t), 2.8 (m), 1.9 (s); ¹⁹F NMR(d₆-acetone): −112.7 (s), −119.8 (s).

Example 4 Copolymerization of triphenylsulfonium1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate (Exemplarypolymer)

2-Phenyl-2-propyl methacrylate (3.32 g, 16.25 mmol),alpha-(gammabutyrolactone) methacrylate (4.40 g, 23.75 mmol),3,5-bis(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)cyclohexylmethacrylate (3.13 g, 6.25 mmol), and triphenylsulfonium1,1,2,2-tetrafluoro-4-(methacryloyloxy)butane-1-sulfonate (50 wt. %solution in acetonitrile; 4.17 g, 3.75 mmol) were dissolved in 16.8 g ofethyl lactate/cyclohexanone (70/30 v/v).2,2-Azobis(2,4-dimethylvaleronitrile) (1.24 g, 3.75 mmol) was dissolvedin the monomer solution. A small amount (˜5 mL) of monomer solution wasintroduced to a vessel pre-heated in an 80° C. oil bath and, after 5min., the remainder of the monomer solution was fed into the vessel over4 hours. The reaction mixture was heated for an additional 2 hours. Thereaction solution was cooled to room temperature and precipitated into a1 L mixture of agitated methyl t-butyl ether and 2-propanol (90/10 v/v).The resultant white powder polymer was isolated by vacuum filtration anddried in a vacuum oven at 45° C. for 48 hours (yield 7.3 g, 58%).

Evaluation of copolymer. DUV evaluation of a photoresist containing thepolymer of Example 4. The polymer of Example 4 (0.61 g) was dissolved in15.40 g of ethyl lactate and 3.82 g of cyclohexanone (70:30 w/w) and0.12 g of a 1% (w/w) solution of tetramethylammonium salicylate in ethyllactate and 0.06 g of a 1% (w/w) solution of POLYFOX 656 surfactant wereadded. The solution was filtered through a 0.2 micrometer TEFLON filter.

The above photoresist formulation was lithographically processed asfollows. The formulated resist was spin-coated using TEL ACT-8 (TokyoElectron) coating track onto a 200 mm silicon wafer having a bottomantireflective coating (BARC) thereon (for 248 nm exposure, 60 nm of AR™9 antireflective, Rohm and Haas Electronic Materials LLC; or 25 nm anorganic underlayer for EUV), and soft baked at 120° C. for 60 seconds(for DUV exposure) or 130° C. for 60 seconds (for EUV exposure), to forma resist film having a thickness of about 50 nm (for DUV exposure) or 60nm (for EUV exposure). The photoresist layer was exposed through aphotomask using a KrF excimer laser (Canon) operating at 248 nm, orusing EUV radiation (eMET) operating at 13.4-13.5 nm, and the exposedlayers were post-exposure baked (PEB) at 90° C. for 60 seconds. Thecoated wafers were next treated with a metal ion-free base developer(CD-26 Developer from Rohm and Haas; 0.26 N aqueous tetramethylammoniumhydroxide solution) for 60 seconds (DUV exposure) or 30 seconds (EUVexposure) to develop the photoresist layer. The dose-to-clear value (E₀)obtained for DUV exposure was 2.7 mJ/cm², and for EUV exposure was 3.6mJ/cm².

FIG. 3 shows the DUV contrast curve (plot of film thickness (inAngstroms) versus exposure dose (in mJ/cm²) for the above formulatedpolymer of Example 4. As seen in the contrast curve, the dose-to-clear(E₀) obtained for the polymer is 2.7 mJ/cm².

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other. The suffix “(s)”as used herein is intended to include both the singular and the pluralof the term that it modifies, thereby including at least one of thatterm. “Optional” or “optionally” means that the subsequently describedevent or circumstance can or cannot occur, and that the descriptionincludes instances where the event occurs and instances where it doesnot. As used herein, “combination” is inclusive of blends, mixtures,alloys, or reaction products. All references are incorporated herein byreference.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Further, it should further be noted that the terms “first,”“second,” and the like herein do not denote any order, quantity, orimportance, but rather are used to distinguish one element from another.

1. A compound having the formula (I):

wherein each R¹, R², and R³ is independently H, F, C₁₋₁₀ alkyl,fluoro-substituted C₁₋₁₀ alkyl, C₁₋₁₀ cycloalkyl, or fluoro-substitutedC₁₋₁₀ cycloalkyl, provided that at least one of R¹, R², or R³ is F; n isan integer of from 1 to 10, A is a halogenated or non-halogenated C₂₋₃₀olefin-containing polymerizable group, and G⁺ is an organic or inorganiccation.
 2. The compound of claim 1, having the formula (II) or (III):

wherein each R², R³ and R⁴ is independently H, F, C₁₋₁₀ alkyl, or C₁₋₁₀fluoroalkyl, n is 1 or 2, A-O is a C₃₋₂₀ vinyl carboxylate group, ahydroxy-containing C₅₋₂₀ vinyl carboxylate group, or a C₇₋₂₀ vinylaryloxy compound, and G⁺ is an organic or inorganic cation.
 3. Thecompound of claim 1, having the formula (IV), (V), (VI), (VII), or(VIII):

wherein each R², R³, R⁴, R⁵, R⁶, and R⁷ is independently H, F, C₁₋₁₀alkyl, or fluoro-substituted C₁₋₁₀ alkyl, each R⁸ is independently F,C₁₋₁₀ alkyl, or fluoro-substituted C₁₋₁₀ alkyl, L is a halogenated ornon-halogenated C₁₋₃₀ alkylene group, C₂₋₃₀ alkenylene group, monocyclicor polycyclic C₃₋₃₀ cycloalkylene group, monocyclic or polycyclic C₆₋₃₀arylene group, or monocyclic or polycyclic C₇₋₃₀ alkylene-arylene group,k and l are each independently integers of 0 to 5, and where k is 0, lis 1, m is an integer of 0 to 4, n is 1, 2, or 3, and G⁺ is an organicor inorganic cation.
 4. The compound of claim 1, having the formula(IX), (X), (XI), (XII), or (XIII):

wherein R⁵ and R⁷ are independently H, F, C₁₋₁₀ alkyl, orfluoro-substituted C₁₋₁₀ alkyl, and G⁺ is an organic or inorganiccation.
 5. The compound of claim 1, wherein G⁺ is an alkali metalcation, an alkaline earth metal cation, a main group metal cation, atransition metal cation, an ammonium ion, an alkylammonium ion, animinium ion, a guanidinium ion, an alkylphosphonium ion, an onium cationof sulfur or iodine, or a combination comprising at least one of theforegoing.
 6. The compound of claim 1, wherein G⁺ is a cation havingformula (XIV):

wherein in formula (XIV), X is S or I, each R⁰ is independently ahalogenated or non-halogenated group comprising a C₁₋₃₀ alkyl group; apolycyclic or monocyclic C₃₋₃₀ cycloalkyl group; a polycyclic ormonocyclic C₆₋₃₀ aryl group; or a combination comprising at least one ofthe foregoing, optionally two R⁰ groups are further attached to oneanother by a single bond where each R⁰ group is independently amonocyclic C₆₋₃₀ aryl group, and a is 2 or 3, wherein when X is I, a is2, or when X is S, a is
 3. 7. The compound of claim 1, wherein G has theformula (XV), (XVI), or (XVII):

wherein X is I or S, R⁹, R¹⁰, R¹¹, and R¹² are each independentlyhydroxy, nitrile, halogen, C₁₋₁₀ alkyl, C₁₋₁₀ fluoroalkyl, C₁₋₁₀ alkoxy,C₁₋₁₀ fluoroalkoxy, C₆₋₂₀ aryl, C₆₋₂₀ fluoroaryl, C₆₋₂₀ aryloxy, orC₆₋₂₀ fluoroaryloxy, Ar¹ and Ar² are independently C₁₀-30 fused orsingly bonded polycyclic aryl groups; R¹³ is a lone pair of electronswhere X is I, or a C₆₋₂₀ aryl group where X is S; p is an integer of 2or 3, wherein when X is I, p is 2, and where X is S, p is 3; q and r areeach independently an integer from 0 to 5; and s and t are eachindependently an integer from 0 to
 4. 8. A polymer comprising thecompound of claim
 1. 9. A sultone precursor for a monomer, having theformula (XVIII):

wherein each R is independently F, C₁₋₁₀ alkyl, fluoro-substituted C₁₋₁₀alkyl, C₁₋₁₀ cycloalkyl, or C₁₋₁₀ fluoro-substituted C₁₋₁₀ cycloalkyl,provided that at least one R is F; n is an integer of from 0 to 10, andm is an integer of 1 to 4+2n.
 10. A monomer comprising the reactionproduct of the sultone precursor of claim 9 and an oxyanion of acarboxy- or hydroxy-containing halogenated or non-halogenated C₂₋₃₀olefin-containing compound.